Method and means for producing concrete pipes



July 30, 1935. BRADEN 2,009,604

METHOD AND MEANS FOR PRODUCING CONCRETE PIPES Original Filed Nov. 14, 1929 2 Sheets-Sheet l nior i In ve J/Jem w rwa'ze Q By Attorney 12337 3% 1935. A. L. BRADEN ,6

METHOD AND MEANS FOR PRGDUCING CONCRETE PIPES Original Filed Nov. 14, 1929 2 Sheets-Sheet 2 lot A itomey Patented July 30, 1935 METHOD AND'MEANS FOR PRODUCING CONCRETE PIPES Allen L. Braden, Los Angeles, Calif., assignor of one-half to Hans H. Jorgensen, Los ,Angeles,

Calif.

Application November 14, 1929, Serial No. 407,226

Renewed December 21, 1934 6 Claims.

My invention relates to a method of and means for producing spun concrete pipes and has particular reference to the manufacture of spun concrete pipes having a connecting bell formed integrally therewith.

In the construction of concrete pipes the usual method followed is to employ a form constructed in accordance with the configuration of the outside ofthe concrete pipe to be produced, into which form is introduced a charge of concrete mix, and to thereafter rotate the form so that the concrete is pressed outwardly against, the form by centrifugal force to produce what is known as a spun pipe. 7

The manufacture of straight sections of pipe by the above noted method is comparatively simple' but great difficulty has been encountered in attempting to cast by this method a pipe, with a bell or connecting member formed integrally therewith, since the bell must be of larger diameter than the main body of the pipe, and the opening therethrough must be larger than the opening through the main body of the pipe.

The employment of a form having an enlarged end thereon, with an interior core for the purpose of forming the inner circumference of the bell has been attempted, but pipe constructed by such methods is unsatisfactory because the spinning of the pipe tends to trap the lighter particles of the mix, the water and air, between the core and that portion of the form surrounding the bell, which causes the structure of the bell to be composed largely of slurry. Hence, the bell portion of the pipe is of inferior strength as compared to the main body of the pipe and in some cases the entrapped water prevents the aggregate from entering into the bell portion of the pipe, so that the bell is but partially formed and is of unsound construction.

It is an object of my invention to provide a method of casting by the spinning process a pipe having a bell formed integrally therewith which method will produce a bell construction equal in composition and strength to that of the main body of the pipe.

Another object of my invention is to provide a core or insert which may be placed within the pipe formed during the casting process and which may be readily removed from the form.

Another object of my invention is to provide a core which may be located within the form during the casting of the pipe, which form is so constructed as to permit the escape of water from the bell portion of the form.

Other objects of my invention will be apparat the left hand end in accordance with my improved method.

Figs. 3 and 4 are transverse sections taken on the lines 3-3 and 44 respectively of Fig. 1.

Fig 5 is a fragmentary end view showing the green concrete with the annular flanges arranged in the bell portions and subsequently removed to relieve said portions of internal obstructions.

In the drawings; in Fig. 1, the reference character 6 designates the cylindrical portion of the form which is preferably constructed of sections, and at one end is a removable washer I. At the opposite end is a sectional ring-like portion 8 which defines the external surface of the bell joint. In between is a part 9 which forms the taper between the bell end and the body.

At the left hand end is a closing ring In to which one leaf of a hinge II is connected. The other leaf of the hinge is elongated and extends across the part 8 and is detachably connected with a keeper I3 on the tapered part 9 of the form.

The principal novel feature of my construction resides in the provision of a mold ring assembly which embodies a plurality of longitudinally spaced units I 4, each unit being made up of companion sections I5 and I6. These sections are of annular construction and disposed in meeting contact. By preference the sections I5 and I6 are made up of individual separable segments to facilitate removal and. application.

Morever, the multiple units I4 of the complete assembly, are fastened together by the tie strips or bars I I. I also call attention to the fact that the segments which make up the sections I5 and I6 are of tapered cross section. The result is that when the assembly is in place, it constitutes a mold for shaping a bell joint or coupling of the configuration seen in Fig. 5.

With this arrangement, it will be understood that the tubular body portion of the pipe as indicated at I8 will be of usual configuration and will be joined by a relatively thickened tapered portion I 9 with the enlarged part 20 of the bell end. Moreover by the presence of the knock-down ring assembly, I also form the inwardly projecting,

longitudinally spaced, annular, tapered, flanges 21. These are however, removed, while the concrete is still green, thus leaving a roughened internal bore in the part 20, as seen in the finished product represented in Fig. 2.

The gist of the invention, it will be understood, is in the provision of the novel ring assembly, wherein the units are made up of companion sections and the sections themselves made of separable segments as seen clearly in Fig. 3. Thus by removing the connecting strips H, the segments will drop out to facilitate removal, leaving the flanges 2|.

A careful consideration of the description in connection with the drawings, will enable the reader, to obtain a clear understanding of the construction, the method of production, and the means for accomplishing it. Therefore, a more lengthy description is regarded. as unnecessary.

Minor changes in shape, size, materials, and rearrangement of elements, coming within the field of invention claimed may be resorted to in actual practice if desired.

Having thus described my invention, what I claim as new is:

1. In a device for centrifugally producing from a plastic mix a structure having two or more different inner diameters, an outer form for determining the outer configuration of said structure, and an inner form for determining the inner configuration thereof, said inner form having radially extending openings therethrough.

2. In a device for centrifugally producing from a plastic mix astructurehaving two or more different inner diameters, an outer form for determining the outer configuration of said structure, and an inner form for determining the inner configuration thereof, said inner form having an inner diameter substantially equal to the smallest inner diameter of said structure and said inner form having radially extending openings therethrough.

3. In a device for centrifugally producing from a plastic mix a structure having two or more different inner diameters, an outer form for determining the outer configuration of said structure, and an annular inner form having one or more outer diameters to conform with the desired interior configuration of the structure and having a plurality of passages extending from the interior of said inner form to the outer circumference thereof.

4. In a device for centrifugally producing an integral pipe and bell from a concrete mix, an outer form for determining the outer surface of said pipe and said bell, and an annular bell form to determine the inner surface of the bell, said bell form having a plurality of passages for concrete extending radially therethrough.

5. In a device for centrifugally producing an integral pipe and bell from a plastic material, an outer form for determining the outer surface of said pipe and said bell, and an annular bell form to determine the inner surface of the bell, said bell form having an inner diameter substantially equal to the inner diameter of the pipe and having a plurality of passages for concrete extending from the outer surface of said bell form to the inner surface thereof.

6. The method of forming an integral pipe and bell from a concrete mix by the centrifugal process which consists in spinning the concrete mix in a rotating outer form, inserting in said form an inner form of a size to form the inner surface of the bell and having an inner diameter substantially equal to the inner diameter of the pipe and allowing the lighter constituents of the mix to pass through said inner form.

ALLEN L. BRADEN. 

